you really have to use lenses with manual iris rings and then *lock* exposure - this will allow you to control iris, shutter and iso. it's a bit of a pain, but there you have it. it's a camera best suited to shooting full manual landscapes and stuff like that. canon are a bunch of wieners for all the restrictions they slapped onto the 5D2, but there are ways to make it work.

on the plus side, you can sit there and shoot 1080p video for hours and hours before your batteries and CF cards will give out on you.